Circular piston combustion engine

ABSTRACT

The invention relates to a circular piston combustion engine having a housing composed of at least one shell and heads parallel to each other, each shell being arranged between two heads and enclosing a chamber in which a piston is rotatably arranged, and coolant passages being provided in the heads, communicating with a sump attached to the bottom of the housing.

United States Patent 3,628,900

[72] Inventors Rolf Lechler; [56] References Cited will! Leitermann,both of Neckarsulm, UNITED STATES PATENTS I 21 1 gig? 3,007,460 11/1961Bentele et al. 418/83 3,286,700 11/1966 Froede 418/61 [22] Filed Feb. 6,1970 3,289,647 12/1966 Turner et al. 418/61 Patemed 3 308 793 3/1967 1m418/89 [73] Assignees Audi NSU Auto Union Aktiengesellschatt 33599522/1967 J 123/8 07 Nechrsulm, wumemberg Germany; ones eta Wankel GmbllPrimary Examiner-Carlton R. Croyle Lindau an Bodensee, Germany AssistantExaminer-John J. Vrablik [32] Priority Feb. 8, 1969 Attorney-Kane,Dalsimer, Kane, Sullivan & Kurucz [33] Germany [31] P19064316 ABSTRACT:The invention relates to a circular piston combustion engine having ahousing composed of at least one shell [54] CIRCULAR PISTON COMBUSTIONENGINE and heads parallel to each other, each shell being arranged 4Claims, 2 Drawing Figs. between two heads and enclosing a chamber inwhich a piston 52 us. c1 418/88, is m'alably and Passages being Pmvlded123/807, 123/195 184/63 the heads, communicating with a sump attached tothe bottom 51 1111. C1 F0lc 21/04, hwfimg- F04c 29/02, F04c 29/04 [50]Field of Search 418/83, 88,

mama] 115021 I97! $628,900

Fig.7

INVE NTO RS ROLF LECHLER wuu= LEWERMANN ATTOR CIRCULAR PISTON COMBUSTIONENGINE In reciprocating piston combustion engines, tight attachment ofthe oil sump presents no difficulties, since the crankcase is open atthe bottom and its bottom edge lies in a plane, so that a good sealbetween sump and crankcase can be achieved with a flat gasket. Incircular piston combustion engines, on the other hand, there is no opencrankcase, and construction of the engine housing so that its bottomlies in a plane would require additional material, owing to thesubstantially oval shape of the housing, thus increasing weight andspace requirements.

The object of the invention is to provide a circular piston combustionengine of the aforementioned kind wherein the attachment of a sump forthe cooling liquid is simplified and a dependable seal is obtained. Thisobject is accomplished, according to the invention, in that the passagesin the heads terminate in a common plane at the bottom of the housingand in that the sump consists of a self-contained unit bolted along itsperiphery to the housing and having on top an opening for each head,communicating with the passage in that head and encircled by a packingring which, when the fastening bolts are tightened, tightly encirclesthe mouth of the passage in the head.

Whereas in the conventional construction and arrangement forreciprocating piston combustion engines a gasket must be provided allthe way around the sump, with a correspondingly long sealing length, thetightening of which requires a great many closely spaced bolts, in theproposal according to the invention sealing is provided only at thepoints where the cooling liquid leaves the heads, by placing simplepacking rings around the mouths of the passages in the heads. Thesepacking rings are compressed when the sump is bolted on, where owing tothe short sealing length of each ring a comparatively small number ofbolts suffices for a dependable fastening and seal.

The openings in the top of the sump are preferably provided with arolled edge around which the packing ring is placed. This considerablysimplifies assembly.

Preferably, a suction cage is arranged in the sump, its suction lineterminating in one of the openings in the top of the sump, the passagecorresponding to this opening in the head in question serving as suctionpassage for a circulating pump. Thus, the sump becomes a completecomponent with all openings and fittings required for return of coolingliquid from the several heads to the cooling liquid circulating pump.

An embodiment of the invention will now be explained by way of examplewith reference to the drawing. In the drawings:

FIG. 1 shows a partial longitudinal section through the housing of atreble circular piston combustionengine at the line ll in FIG. 2;.and

FIG. 2 shows a section at the line 2-2 of FIG. 1.

The housing of the circular piston combustion engine shown consists ofouter heads 1 and 2 and inner heads 3 and 4. Between neighboring heads 1and 3, 3 and 4, 4 and 2, jackets 5 are arranged, each having amultilobate inner surface 6 in the form of a bilobate epitrochoid andenclosing a chamber 6a. The housing is traversed by an eccentric shafthaving a number of eccentrics corresponding to the number of jackets 5,on each of which a triangular piston is rotatably mounted. The pistonsare oil cooled, the cooling oil being supplied to the pistons throughpassages in the eccentric shaft and returned through passages 7 in heads2, 3 and 4. The passages 7 terminate in a common plane 8 at the bottomof the housing. Heads 1, 2, 3 and 4 are provided with lugs 9 to which aselfcontained oil sump I0 is bolted the top 11 of which has an opening12 for each head 1, 2, 3 and 4, communicating with the passage 7 in thatparticular head. Each opening is provided with a rolled edge I3,encircled by a packing ring I4. When the fastening bolts 15 aretightened, the packing rings 14 are deformed and provide a dependableseal. The pressing of the packing rings 14 against the bottoms of theheads is assisted by the concaye shape of the top 11 of the sump 10.

In the 011 sump 10, a suction cage 161s arranged, whose suction line 17terminates in an opening I8 in the top 11 of the sump 10, the passage I9in head 1, matching this opening, being intended as a suction passagefor a circulating pump not shown. The connection of the suction line 17to suction passage 19 is likewise sealed with a packing ring 14.

The sump 10 consists of two sections 10a and 10b, rolled onto each otherafter insertion of suction cage 16 with suction line 17 and thus forminga selfcontained unit. 20 designates a strut for the suction cage 16.

The invention may, of course, be employed likewise for circular pistoncombustion engines having only one shell, or more than three shells, bysimply changing the dimensions of the oil sump and the number ofopenings in its top.

We claim:

1. A circular piston combustion engine having a housing comprised of atleast one shell and heads parallel to each other, each shell beingarranged between two heads and enclosing a chamber in which a piston isrotatably arranged, and coolant passages being provided in the heads,communicating with a sump attached to the bottom of the housing, thepassages in the heads terminating in a common plane at the bottom of thehousing, tightenable fastening means, the sump being a self-containedunit fastened to the housing along its periphery by said fastening meansand having on its top an opening for each head communicating with thepassage in that head and each opening encircled by packing means which,when the fastening means are tightened, sealingly encircles the mouth ofthe passage in that head.

2. A circular piston combustion engine accordingly to claim 1 whereinthe edges of the openings are rolled up.

3. A circular piston combustion engine according to claim 1 wherein thetop of the sump is concave.

4. A circular piston combustion engine according to claim 1 wherein asuction cage is arranged in the sump, its suction line terminating in anopening in the top of the sump, and the passage matching said opening inthe associated head serving as a suction passage for a circulating pump.

1. A circular piston combustion engine having a housing comprised of atleast one shell and heads parallel to each other, each shell beingarranged between two heads and enclosing a chamber in which a piston isrotatably arranged, and coolant passages being provided in the heads,communicating with a sump attached to the bottom of the housing, thepassages in the heads terminating in a common plane at the bottom of thehousing, tightenable fastening means, the sump being a self-containedunit fastened to the housing along its periphery by said fastening meansand having on its top an opening for each head communicating with thepassage in that head and each opening encircled by packing means which,when the fastening means are tightened, sealingly encircles the mouth ofthe passage in that head.
 2. A circular piston combustion engineaccordingly to claim 1 wherein the edges of the openings are rolled up.3. A circular piston combustion engine according to claim 1 wherein thetop of the sump is concave.
 4. A circular piston combustion engineaccording to claim 1 wherein a suction cage is arranged in the sump, itssuction line terminating in an opening in the top of the sump, and thepassage matching said opening in the associated head serving as asuction passage for a circulating pump.